In November, 1959, Truman Capote (Philip Seymour Hoffman), the author of Breakfast at Tiffany's and a favorite figure in what is soon to be known as the Jet Set, reads an article on a back page of the New York Times. It tells of the murders of four members of a well-known farm family?the Clutters?in Holcomb, Kansas. Similar stories appear in newspapers almost every day, but something about this one catches Capote's eye. It presents an opportunity, he believes, to test his long-held theory that, in the hands of the right writer, non-fiction can be as compelling as fiction. What impact have the murders had on that tiny town on the wind-swept plains? With that as his subject?for his purpose, it does not matter if the murderers are never caught?he convinces The New Yorker magazine to give him an assignment and he sets out for Kansas. Accompanying him is a friend from his Alabama childhood: Harper Lee (Catherine Keener), who within a few months will win a Pulitzer Prize and achieve fame of her own as the author of To Kill a Mockingbird.

Though his childlike voice, fey mannerisms and unconventional clothes arouse initial hostility in a part of the country that still thinks of itself as part of the Old West, Capote quickly wins the trust of the locals, most notably Alvin Dewey (Chris Cooper), the Kansas Bureau of Investigation agent who is leading the hunt for the killers. Caught in Las Vegas, the killers?Perry Smith (Clifton Collins Jr.) and Dick Hickock (Mark Pellegrino)?are returned to Kansas, where they are tried, convicted and sentenced to die. Capote visits them in jail. As he gets to know them, he realizes that what he had thought would be a magazine article has grown into a book, a book that could rank with the greatest in modern literature. His subject is now as profound as any an American writer has ever tackled. It is nothing less than the collision of two Americas: the safe, protected country the Clutters knew and the rootless, amoral country inhabited by their killers. Hidden behind Capote's often frivolous fa?ade is a writer of towering ambition. But even he wonders if he can write the book?the great book?he believes destiny has handed him. "Sometimes, when I think how good it could be," he writes a friend, "I can hardly breathe."